Journal article
Relationship between patient variables and plasma clozapine concentrations: a dosing nomogram
Biological psychiatry (1969), Vol.44(8), pp.733-738
10/15/1998
DOI: 10.1016/S0006-3223(97)00531-3
PMID: 9798077
Abstract
Background: Previous work has suggested factors such as gender, smoking behavior, dose, and age affect the amount of drug a patient requires to achieve a desired plasma concentration of clozapine. Plasma clozapine concentrations ranging from 350 to 504 ng/mL in treatment-refractory schizophrenics and schizoaffective patients produce response rates ranging approximately 55–80%. Without the aid of clozapine plasma concentration monitoring, 3–6 months are recommended for a therapeutic clozapine trial. Data suggest that the lag time to response can be reduced by administering a dose that produces a therapeutic clozapine concentration.
Methods: To generate a clozapine dosing nomogram to predict clozapine steady-state plasma concentrations, a cohort of 71 patients was collected via retrospective chart review and/or patient interview. Clozapine steady-state plasma concentrations and demographic variables were obtained. Multiple-linear regression was utilized to examine the relationship between the plasma clozapine concentration and the independent variables.
Results: The dosing model that optimally predicted steady-state clozapine plasma concentrations included the variables dose (mg/day), smoking (yes = 0 and no = 1), gender, and a dose–gender interaction variable. The model explained 47% of the variance in the clozapine concentrations (
F = 14.42,
p < .001,
r
2 = .47). Two equations, one for male subjects, i.e., clozapine (ng/mL) = 111 (smoke) + 0.464 (dose) + 145, and one for female subjects, i.e., clozapine (ng/mL) = 111 (smoke) + 1.590 (dose) − 149, were derived to predict clozapine steady-state plasma concentrations to serve as a clozapine dosing guide for clinicians.
Conclusions: A clozapine dosing nomogram was constructed as a clinical aid to facilitate clozapine dosing.
Details
- Title: Subtitle
- Relationship between patient variables and plasma clozapine concentrations: a dosing nomogram
- Creators
- Paul J. Perry - University of IowaKristine A. Bever - University of IowaStephan Arndt - University of IowaMichael D. Combs - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Biological psychiatry (1969), Vol.44(8), pp.733-738
- DOI
- 10.1016/S0006-3223(97)00531-3
- PMID
- 9798077
- ISSN
- 0006-3223
- eISSN
- 1873-2402
- Publisher
- Elsevier Inc
- Number of pages
- 6
- Language
- English
- Date published
- 10/15/1998
- Academic Unit
- Pharmacy; Psychiatry; Biostatistics; Nursing; Injury Prevention Research Center
- Record Identifier
- 9985132185502771
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